Hydraulic coupling

ABSTRACT

A hydraulic coupling employing a polymeric elastomeric sealing member to provide an excellent seal under pressure. The polymeric elastomeric seal additionally has high resistance to acids, alkalis, hydrocarbons, ketones, ethers, esters, alcohols and salt solutions. The sealing member has the elasticity to return to its normal physical condition after pressure is removed.

This application is a division of U.S. patent application Ser. No.08/672,145 filed Jun. 27, 1996 which is a continuation-in-part of U.S.patent application Ser. No. 08/197,635 filed Feb. 17, 1994 now U.S. Pat.No. 5,556,139 which is a continuation-in-part of Ser. No. 08/145,688filed Oct. 29, 1993 entitled "Hydraulic Coupling" now abandoned.

The invention relates in general to hydraulic couplers and particularlyto one uniquely adapted for use in subsea applications and other harshenvironments.

The prior art of hydraulic couplers illustrate the many and variedsealing members that have been used to seal between male and femalemembers. The sealing members have varied from soft materials such asfelt, rubber and soft synthetic resinous materials to hard metalmaterials such as stainless steel and other metal alloys.

These materials have met with varying success and in most instances theuse of one material for a given advantage is a trade off because it alsohas a given disadvantage. For example, the rubbers and soft syntheticresinous materials do not have sufficient strength to withstand highpressure applications and metal seals are so hard as to scratch or marthe surfaces on the male or female member which they engage to providethe seal. The metal seals also have a tendency to interact with sandand/or to scratch the coupler surfaces.

The purpose and object of this invention is to provide a sealing memberin combination with a male and female member of a coupler which fitsbetween the extremes outlined above.

An object of the invention is to provide a sealing member which hassufficient strength to handle high pressure applications but will notscratch or otherwise mar the coupler surfaces. Another object of theinvention is to provide a sealing member constructed of a polymericelastomeric material which has physical characteristics to accomplishthe objects stated herein.

Another object of the invention is to prevent the blowout of the sealingmember during disconnection of the male and female members.

The sealing member of the invention has the correct deformationqualities to provide an excellent seal under pressure but also has theelasticity to return to its normal physical condition after pressure isremoved.

In the instant invention, it is desirable that the opening in thesealing member which the male member "sees" be the same diameter eachtime the male and female member are connected. In the use of metalsealing members or rings the opening gradually becomes larger and largerwith each use resulting in a less and less effective seal against flowof fluid along the interface between the sealing member and the movablecoupler part.

Another object of the invention is to provide polymeric seals which maybe employed in a balanced coupler.

Another object of the invention is to provide a plurality of polymericseals which seal against the escape of fluid from within the couplingand from the entrance of seawater outside the coupling.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a hydraulic coupler partially insection and with the male and female members connected;

FIG. 2 is an enlarged fragmentary section of a portion of a hydrauliccoupler illustrated in FIG. 1;

FIG. 3 is a view illustrating the female coupler member of FIG. 1 in thedisconnected condition;

FIG. 4 is a view illustrating the male coupler of FIG. 1 in thedisconnected condition;

FIG. 5 is an enlarged fragmentary sectional view similar to FIG. 2 butshowing a modification of the invention illustrated in FIG. 2;

FIG. 6 is an enlarged fragmentary section illustrating the sealingmember shown in FIG. 5 as applied to a balanced coupler;

FIG. 7 is an enlarged fragmentary view of a still further modificationof the invention over that shown in FIGS. 2 and 5;

FIG. 8 is an elevational view of another hydraulic coupler partially insection and with the male and female members connected;

FIG. 9 is an enlarged fragmentary section of a portion of the hydrauliccoupler illustrated in FIG. 8 illustrating a sealing arrangementemploying first, second and third seals;

FIG. 10 is a view illustrating the female coupler member of FIG. 8 inthe disconnected condition;

FIG. 11 is a view illustrating the male coupler member of FIG. 8 in thedisconnected condition;

FIG. 12 is an elevational view of another hydraulic coupler partially insection and with the male and female members connected;

FIG. 13 is an enlarged fragmentary section of a portion of a hydrauliccoupler illustrated in FIG. 12 illustrating a sealing arrangementemploying first, second and third seals a modified retainer;

FIG. 14 is a view illustrating the female coupler of FIG. 12 in thedisconnected condition;

FIG. 15 is a view illustrating the male coupler of FIG. 12 in thedisconnected condition;

FIG. 16 is a further enlarged view of the seal arrangement of thehydraulic coupler illustrated FIG. 8; and,

FIG. 17 is a further enlarged view of the seal arrangement of thehydraulic coupler illustrated in FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

One hydraulic undersea coupler is illustrated in FIGS. 1, 3 and 4 of thedrawings and has been identified generally by the reference numeral 10.The coupler includes generally a female member 14 and a male member 20movable between coupled condition illustrated in FIG. 1 and uncoupledcondition illustrated in FIGS. 3 and 4. The female member includes amain body 14 and internal insert member 15 which is threadably securedin place by thread 16 as shown in FIGS. 1 and 3. In similar fashion, themale member includes a main body 20 and includes an internal insertmember 24 which is threadably secured in the position shown in FIGS. 1and 4 by means of threads 25.

First wall means 23 define a first passage or bore through the femalemember 14 which provides for the flow of fluid from one open end of thefemale member through the passage and to the other end of the femalemember. In like fashion, second wall means 26 are provided in the malemember to define a second passage or bore through the male member toprovide for the flow of fluid through one end of the male member to theother end thereof. See FIG. 1.

A first check valve 80 is provided in the female member as shown inFIGS. 1 and 3 and a spring 81 normally biases the first check valve toits closed condition as illustrated in FIG. 3. A valve seat 83 isprovided in the passage of a bore 23 in the female member and this isessentially a surface which is engaged by the check valve andparticularly an elastomeric portion 84 on the check valve. The checkvalve 80 is provided with a plurality of annularly spaced ports 82 whichprovide for the flow of fluid through the check valve when it is in itsopen condition as illustrated in FIG. 1.

In like fashion, the male member is provided with a second check valve86 which is constantly biased or urged to closed condition by a spring87. See FIG. 4. The open condition of the check valve 86 is illustratedin FIG. 1 and its closed condition is shown in FIG. 4. The passage orbore 26 of the male member is provided with a valve seat 89 whichengages the check valve 86 and particularly an elastomeric portion 90carried by the check valve when it is in closed position as shown inFIG. 4. The check valve 86 is provided with a plurality ofcircumferentially spaced ports 88 which provide for the passage of fluidthrough check valve 86 in its open condition as shown in FIG. 1.

The first wall means 23 which defines the first passage or first bore inthe female member 14 in the end of the female member closest to wherethe male member 20 is inserted into the female member is provided with ashoulder 30 which is generally shown in FIGS. 1 and 3 and is shown insubstantial detail in the enlarged fragmentary view of FIG. 2.

The shoulder 30 is defined by first and second radially spaced andaxially extending surfaces 32 and 34 and first and second axially spacedand radially extending surfaces 36 and 38. The male member 20 has afirst end portion 21 (FIG. 2) which resides in the first passage or bore23 of the female member 14 in the coupled condition of the coupler asillustrated in FIG. 1.

The first end portion 21 has an external circumferentially extendingsurface 22 spaced from the first axially extending surface 32 andlocated close to the second axially extending surface 34 in the coupledcondition best shown in FIGS. 1 and 2. The external surface 22 of themale, the first axially extending surface 32, the first radiallyextending surface 36, and the first end surface 66 of retainer 64 definean annularly extending space or annulus 42. An annularly extendingsealing member or seal 50 resides in the space 42. As seen in FIG. 2,this annularly extending sealing member in cross section is generallyrectangularly shaped and as mentioned before, resides in the space 42.The sealing member 50 has inner and outer circumferentially extendingsurfaces 54 and 55, respectively, lying adjacent the external surface 22of the male member and the first axially extending surface 32,respectively. The sealing member 50 also has first and second endsurfaces 60 and 61, respectively, with the first end surface beinglocated adjacent the first radially extending surface 36.

An annularly extending annular retainer 64 is provided as shown whichhas first and second axially spaced end surfaces 66 and 67,respectively, (FIGS. 2 and 3) with the first end surface 66 beinglocated adjacent the second end surface 61 of the sealing member to holdthe sealing member in the annular space 42. An adaptor 69 (FIGS. 1 and3) is threadably connected by means of threads 73 to the body 14 of thefemale member and serves to hold the annular retainer 64 and the sealingmember 50 in the position illustrated in FIG. 1. A channel shaped seal68 which extends annularly around the coupler is interposed between theadaptor 69 and the annular retainer 64 to assist in sealing against theescape of fluid pressure. As best seen in FIG. 2, a first wall 70extends into the first end surface 60 of the sealing member 50 anddefines a first cavity 71 which faces the first radially extendingsurface 36 of the shoulder and creates a generally C-shaped appearancein cross section. In similar manner, a second wall 76 extends into theouter circumferentially extending surface 55 of the sealing member 50and defines a second cavity 77 facing the first axially extendingsurface 32 of the shoulder and creating a generally U-shaped appearancein cross section. The sealing member 50 of the present invention isconstructed of a polymeric elastomeric material which accomplishes theobjects that have been stated hereinabove in a manner consistent withaccomplishing the teachings of the present disclosure.

In operation and assuming the coupler is in the uncoupled condition asillustrated in FIGS. 3 and 4, and in this condition, the check valves 80and 86 are in the closed condition preventing fluid flow through thefemale member and the male members.

As the male and female members are brought towards coupled condition,the extreme ends of the check valves 80 and 86 engage each other andmove each other to the open condition shown in FIG. 1 against the forceor bias of springs 81 and 87. The male and female members are maintainedmechanically in this connected position by a means not shown orillustrated herein but well understood by those skilled in the art. Inmany instances, the male members are fixedly mounted subsea on aphysical support member and a corresponding plurality of the femalemembers are lowered subsea into the connected position of FIG. 1 andheld together by a means not illustrated.

As the end portion 21 of the male member 20 passes through the innerdiameter of the sealing member 50, the external surface 22 of the malemember travels closely adjacent the inner surface 54 of the sealingmember.

After the male and female member reach their coupled condition asillustrated in FIG. 1 with their respective check valves in opencondition, fluid pressure such as hydraulic fluid is caused to flow, forexample, from the left end of the female member 14 as viewed in FIG. 1through the bore 23, through ports 82 and out through the male memberthrough ports 88 and bore 26 in the male member.

In most circumstances, hydraulic couplers of the type illustrated hereindeal with relatively high hydraulic fluid pressure on the order of fouror five thousand psi up to 10,000 psi. Referring to FIG. 2, this fluidpressure finds its way along surfaces 38, 34 and 36 into the generallyC-shaped cavity 71. This fluid pressure causes the upper and lowerportions of the C-shape to tightly and firmly engage surfaces 32 and 22respectively preventing the escape of hydraulic fluid along surfaces 32and 22.

The U-shaped cavity 77 which is provided in the sealing member 50performs the function of assisting and preventing the escape of fluidpressure along surfaces 32 and 61 under some circumstances. In somecircumstances, annular space 42 is exposed to fluid pressure which maytravel along surfaces 36 and 32 tending to escape past the sealingmember. In these circumstances the fluid pressure will be transmitted tothe U-shaped cavity 77 which forces the right most leg of the U intofirm contact with surface 66 and tends to press surface 55 intoengagement with surface 32 tending to provide a better fluid seal underthese circumstances. Obviously the U-shaped portion of the seal is anadjunct or addition to the sealing member and is not a necessaryinclusion into the sealing member formed by the C-shaped portion of thesealing member which has been defined hereinabove.

FIG. 5 illustrates a modification of the invention and shows a sealingmember 150 residing in the space 42. In similar fashion, it is generallyrectangularly shaped and the inner and outer circumferentially extendingsurfaces in this embodiment have been identified by the referencenumerals 154 and 155, respectively, and they lie respectively adjacentthe surfaces 22 and 32. The first and second end surfaces of the sealingmember 150 in this embodiment, have been identified by the referencenumerals 160 and 161, respectively. The end surface 161 is locatedadjacent the retainer 64.

A first wall 170 extends into the sealing member 160 and defines a firstcavity 171 which faces the surface 36 and creates a generally C-shapedappearance in cross-section. This is quite similar to the constructionshown in FIG. 2. A second wall 176 extends into the innercircumferentially extending surface 154 of the sealing member 150 anddefines a second cavity 177 which faces the external surface 22 of themale member 20. The cavity 177 creates a generally U-shaped appearancein cross-section which may be referred to more properly as an invertedU-shape.

The structure and function of the device within which the seal of FIG. 5is incorporated, namely that of the male and female members, isessentially as described in the functioning of the coupler partsillustrated in FIGS. 1, 3 and 4.

When the male and female members are coupled together in connection withthe structure illustrated in FIG. 5, the C-shaped cavity 171 which isformed in the sealing member 150 functions essentially in the samemanner as described in connection with the C-shaped cavity 71 which isillustrated in FIG. 2.

The inverted U-shaped cavity 177 which is formed in the sealing member150 performs a general sealing function; however, it is particularlyuseful in preventing the entrance of seawater into the internal passagesin the male and female members. At times there may be a tendency forseawater to attempt to gain entrance to the internal passageway formedin the coupler members, for example, through the space identified by thereference numeral 180 in FIG. 5 which depending upon the tolerance mayprovide a clearance between the retainer 64 and the male member 20 andparticularly the first end portion 21 thereof. In the event seawater,which is under a relatively high pressure, gains entrance through thespace 180 to cavity 177 the pressure which enters cavity 177 has atendency to force what is referred herein as a leg or leg portion formedby the second cavity 177 into engagement with the wall of the retainer64 preventing seawater from traveling around the sealing member, forexample, to the space between surfaces 32 and 155.

FIG. 6 illustrates use of the specific embodiment shown in FIG. 5 in abalanced coupler which balanced coupler constructions are known to thoseskilled in the art and may be generally of the type shown in U.S. Pat.No. 5,072,755 issued Dec. 17, 1991.

Referring specifically to FIG. 6 there is shown and illustrated abalanced coupler which includes a female member 187 and a male member189 shown in assembled or connected position. The female member isprovided with a passageway 192 and the male is formed with passageway196. Port 200 in the passageway 196 in the male member and port 201 inthe passageway 192 in the female member provide for the passage of fluidbetween the two members. FIG. 6 illustrates two sealing members 150,more specifically described in connection with FIG. 5, illustrated andlocated in shoulders formed in the female member so as to providesealing engagement between the outer circumferential surface of the malemember 189 and a bore formed in the female member 187. A flow port orspacer 198 which has a port 202 for the passage of fluid is provided andlocated between the two sealing members 150. The spacer 198 is providedwith legs 199 on each side which reside in the cavity 171 in the sealingmembers 150.

The functioning of the sealing members 150 in the balanced coupler 185is essentially that as described in connection with FIG. 5.

It will also be apparent to those skilled in the art that the embodimentof the seal more specifically described in connection with FIG. 2 mayalso be utilized in connection with the balanced coupler disclosed anddescribed in connection with FIG. 6.

FIG. 7 illustrates another modification of the present invention andmore particularly a modification of that illustrated in FIGS. 2 and 5.In the embodiment of FIG. 7 there is illustrated an annularly extendingsealing member 250 which resides in the space again generally referredto as space 42. The sealing member 250 is provided with inner and outersurfaces 254 and 255 which lie respectively adjacent the surfaces 22 and32. The sealing member 250 in like fashion has first and second endsurfaces 260 and 261, respectively, and the first end surface 260 islocated adjacent the surface 36.

In this embodiment the annular retainer is identified by the referencenumeral 264 and the first end surface of the retainer is identified bythe reference numeral 266.

A first wall 270 extends into the sealing member and defines a firstcavity 271. The cavity 271 which is defined is quite similar to thecavity 171 which has been discussed in connection with FIG. 5 and thecavity 71 which has been discussed in connection with FIG. 2.

A second wall 276 extends into the inner surface 254 of sealing member250 and defines a second cavity 277 which faces the circumferentiallyextending surface 22 of the end portion 21 of male member 20. The cavity277 defines generally a U-shape or more properly an inverted U-shape.

The right most end of the sealing member 250 as viewed in FIG. 7 isprovided with a generally radially extending flange 280. The flangeresides in what is referred to as a recess 282 which has been formed inthe female member illustrated in this embodiment.

In this particular embodiment illustrated in FIG. 7, the flange aslocated in the recess 282 and in combination with the annular retainer264 provides an additional sealing function which prevents the passageof or leakage of fluid along the connection between the male and femalemembers. In this particular embodiment, it is possible to not use thesecond cavity 277 which has been illustrated herein and the flange andcavity 271 will function together to provide a satisfactory and suitablesealing arrangement.

FIG. 8 illustrates another modification of the invention. FIG. 8illustrates a coupling 580 which includes male member 20' and a femalemember 14'. Retainer 364, male member 20', and female member 14' formannularly extending space 42'. Seals 350, 450 and 550 reside inannularly extending space 42'. See, FIGS. 8, 9 and 16.

In the embodiment of FIG. 8 there is illustrated three annularlyextending sealing members 350, 450, and 550 which reside adjacent toeach other in space 42'.

Seal members 350 and 550 are constructed of Polyarylether ketone andseal 450 is made of molybdenum-disulfide filled nylon. The space 42' isslightly larger than the seals and therefore may permit them to moveslightly under pressurization.

The space 42', being oversized, ensures that pressure between theinterface of the male member surface 22' and the female member surface34' will act upon the cavity 371 of the first seal. Reference numeral401 indicates the location of the pressure source being described. SeeFIG. 9. Sealing member 350 includes inner and outer surfaces 354 and 355which lie respectively adjacent surfaces 22' and 32'. See FIG. 16.Sealing member 350 has first and second end surfaces 360 and 361,respectively, and the first end surface 360 is located adjacent thesurface 36'. Sealing member 450 has inner and outer surfaces 454 and 455which like the inner and outer surfaces of sealing member 350 also lierespectively adjacent surfaces 22' and 32'. Seal member 450 is a back upseal for seal 350 in the event that the first seal 350 does not sealproperly when, for example, the male and female coupler halfs are in theprocess of engaging. Sealing member 450 includes first and second endsurfaces 460 and 461, respectively. The first end surface 460 is locatedadjacent the second end surface 361 of sealing member 350. Sealingmember 550 includes inner and outer surfaces 554 and 555 which also lierespectively adjacent surfaces 22' and 32'. Sealing member 550 includesfirst and second end surfaces 560 and 561, respectively and the firstend surface is located adjacent the second end surface of sealing member450.

The embodiment of FIGS. 8, 9, 10, 11 and 16 show the annular retainer364 and the first end surface of the retainer is identified by thereference numeral 366. The second end surface 561 of sealing member 550is located adjacent to retainer. See FIGS. 9 and 16.

A wall 370 extends into sealing member 350 and defines a cavity 371. Thecavity 371 which is defined is quite similar to the cavities 71, 171 and271 which have been discussed in connection with FIGS. 2, 5 and 7respectively.

A wall 570 extends into the sealing member 550 and defines a cavity 571.The cavity 571 is quite similar to cavity 371 of sealing member 350above, except cavity 371 is facing in the opposite direction.

Seal 350, sometimes referred to hereinafter as the first seal, includesfirst 351 and second 352 leg portions. FIGS. 9 and 16 illustrates theseal arrangement of FIG. 8 in more detail. FIG. 16 illustrates the threeseals, 350, 450, and 550 in detail. Pressure inside the coupling isapplied to the cavity 371, and hence, legs 351 and 352 of seal 350 inthe same manner as previously described in connection with anotherembodiment. Legs 351 and 352 are forced outwardly to seal againstsurfaces 32' of the female member and 22' of the male member. See FIG.16.

Seal 550, sometimes referred to herein as the third seal includes afirst leg portion 572 and a second leg portion 573. Similarly, pressureoutside the coupling is applied to the cavity 571, legs 572 and 573 ofseal 550. Legs 572 and 573 of seal 550 are forced outwardly to sealagainst surfaces 32' of the female member and 22' of the male member.Seawater, under high pressure at the bottom of the ocean, will attemptto enter the passageways of the hydraulic coupler at points denoted byreference numerals 499 and 500. See FIG. 8. Reference numeral 501denotes a vent in the male half of the coupler. Seal 450, sometimesreferred to herein as the second seal, includes a first leg portion 451and a second leg portion 452. The first and second leg portions of seal450 interfit with seal 350. Seal 450 is interposed between the firstseal 350 and the third seal 550.

FIG. 10 illustrates the female half 14' of the coupling illustrated inFIG. 8 disconnected from the male half 20'. FIG. 10 illustrates thepositioning of seals 350, 450, and 550 and their legs prior toengagement with the male member 20'. FIG. 11 illustrates the male half20' of the coupling illustrated in FIG. 8 disconnected from the femalehalf 14'. FIG. 16 illustrates an enlarged view of the seals 350, 450 and500 in annular space 42'.

The coupling 475 illustrated in FIG. 12 includes three primary seals,650, 750, 850 and an elastomeric O-ring 950. Additionally, the coupling475 includes a male member 20", a retainer 464, and a female member 14".The retainer includes a lip portion 465 which includes an inner surfaceportion 33". The female member 14" includes axially extending, radiallyspaced surfaces 32" and 34", and a radially extending surface 36".

Seals 650 and 850 are made of polyarylether ketone and seal 750 is madeof molybdenum disulfide filled nylon. However, those skilled in the artwill appreciate that any of the materials in the chart of materialsbelow may be employed in combination for any of the seals. The sealarrangement employed in the embodiment of FIG. 12 is different than theembodiment of FIG. 8. Namely, the retainer 464 extends in a lip portion465 above the third seal. Additionally, as the retainer 464 bottoms outor abuts the female member 14" as illustrated in FIG. 12, the seals 650,750 and 850 are held snugly in position. This is in contrast to theembodiment of FIG. 8 which provides room for the seals to positionthemselves in space 42".

Reference numeral 42" is used in FIG. 13 to illustrate the annular spacebounded by the external surface 22" of the male 20", the surface 33" onthe lip 465 of retainer 464, the axially extending surface 32" of thefemale 14", and the radially extending surface 36" of the female member.

Wall means 670 form cavity 671 in first seal 650. First seal 650includes a first leg 652 and a second leg 653. FIG. 13 illustrates thatsecond leg 653 is shorter than first leg 652 of the first seal.Similarly, wall means 870 forms cavity 851 in third seal 850. Third seal850 includes a first leg 852 and a second leg 853. FIG. 13 illustratesthat second leg 853 is shorter than first leg 852.

The first seal 650 includes a first end surface 660 and a second endsurface 661. Similarly, the second seal includes a first end surface 760which interfits with the second end surface 661 of the first seal.Second seal includes a second end surface 761. Third seal 850 includes afirst end surface 860 which interfits with the second end surface 761 ofthe second seal. Third seal 850 includes a second end surface 861. SeeFIG. 13.

Second seal 750 includes a first leg 751 and a second leg 752. The firstend surface 660 abuts the radially extending surface 36" as shown inFIG. 13. Similarly, the second end surface 861 of the third seal abutsthe retainer 464.

Reference numeral 881 in FIG. 13 illustrates the space between theexternal surface 22" of the male and the axially extending surface 34"of the female member from which pressure is applied to cavity 651 of thefirst seal 650. As pressure is applied to cavity 651, the first leg 652is urged radially into sealing engagement with the surface 32" of thefemale member 14" and the second leg 653 is urged radially into sealingengagement with the surface 22" of the male member 20".

Reference numeral 882 in FIG. 13 illustrates the space between theexternal surface 22" of the male and the retainer 464 from whichpressure is applied to cavity 851 of the third seal 850. As pressure isapplied to cavity 851, the first leg 852 is urged radially into sealingengagement with the surface 33" of the retainer 464 and the second leg853 is urged radially into sealing engagement with the surface 22" ofthe male member 20".

The second seal 750 is a back up seal for seal 650 in the event thatseal 650 does not seal properly when, for example, the male and femalecoupler halfs are in the process of engaging.

FIG. 14 illustrates the female half 14" of the coupling illustrated inFIG. 12 in the disconnected condition. FIG. 12 illustrates theelastomeric seal 950 positioned between the retainer 464 and the femalemember 14". Seal 950 prevents entrance of seawater past the threadedconnection of the retainer 464 and the female half 14". FIG. 14 is agood illustration of the seals 650, 750 and 850 prior to engagement withthe male coupler half 20". FIG. 15 illustrates the male half 20"disconnected from the female half 14". FIG. 17 illustrates an enlargedview of the seals 650, 750 and 850 in annular space 42".

FIGS. 14 and 17 illustrate that the second legs 653 and 853 of the first650 and second 850 seals are shorter than their corresponding first legs652 and 852. Shorter legs ensure the application of pressure fromsources 881 and 882 to the respective cavities 651 and 851.

It has been found that in order to bring about the objects of thepresent invention as stated hereinabove that it is necessary that all ofthe sealing members of this invention be constructed of a polymericelastomeric material which has a tensile strength of at least 5000 psiand a flexural modulus of elasticity of at least 300,000 psi. It is alsodesirable that the polymeric material have a high chemical resistance toacids, alkalis, hydrocarbons, ketones, ethers, esters, alcohols, saltsolutions or a combination of chemicals normally found in oilexploration.

The particular materials that have been found to meet the objects of thepresent invention and to meet these specified and desired physical andchemical characteristics are found in the chart that follows below.

Where multiple seals are used as set forth in FIGS. 8, 9, 10, 12, 13,14, 16 and 17, a combination of the seals listed below may be used.

    __________________________________________________________________________                  ELONGATED                                                                     MODULUS                                                                       OF     FLEXURAL                                                                             CHEMICAL                                          MATERIAL TENSILE                                                                            ELASTICITY                                                                           RESISTANCE                                                                           (ROCKWELL)                                                                           HARDNESS                                   __________________________________________________________________________      Poly (aryl                                                                           14500 psi                                                                          150%   550000 1      M99                                          ether-ketone)                                                                 Polyphenylene                                                                        12000 psi                                                                          20-25% 540000-                                                                              1      M93                                          sulfide            600000 psi                                                 Polyamide-                                                                           16000 psi                                                                          5-18% psi                                                                            1,000,000                                                                            2      M119                                         imide                                                                         Molybdenum                                                                            8000 psi                                                                          5-150% 400000 psi                                                                           3      R110                                         disulfide filled                                                              nylon                                                                       __________________________________________________________________________

With the use of a sealing member having the herein described physicaland chemical characteristic in combination with the male and femalemembers of a hydraulic coupler bring about the desired objects asexpressed hereinabove. The opening in the sealing members 50, 150,250,350, 450, 550, 650, 750, and 850 or in other words the innerdiameter of the sealing member which the male member "sees", isessentially the same diameter each time the male member enters thefemale member as they are moved from uncoupled to coupled condition. Asa result the same consistent seal is provided because the sealing memberof the present invention has the qualities to return to the sameconsistent diameter when the members are uncoupled. This overcomes thedisadvantage found in metal sealing members or rings where the openinggradually becomes larger and larger with each uncoupling or useresulting in a less and less effective seal against fluid flow along theinterface between the sealing member and the movable coupler parts.

Material number 1 in the chart is sold under the trademark VICTREX PEEKby ICI Americas Inc. of Wilmington, Del. Material number 2 is sold underthe trademark TECHTRON by The Polymer Corporation of Reading, Pa.Material number 3 is sold under the trademark TORLON by Amoco ChemicalCorporation. Material number 4 is sold under the trademark NYLATRON byThe Polymer Corporation of Reading, Pa.

The present invention prevents the blowout of the sealing members 50,150, 250, 350, 450, 550, 650, 750 and 850 during separation of the maleand female members.

While the invention has been described in combination with embodimentsthereof, it is evident that many alternatives, modifications andvariations will be apparent to those skilled in the art in light of theforegoing description. Accordingly, it is intended to embrace all suchalternatives, modifications and variations that fall within the spiritand scope of the appended claims.

What is claimed is:
 1. A balanced hydraulic coupling comprising a malemember, a female member, a spacer, a first seal and a second seal, afirst and second annulus formed between said male member, said femalemember and said spacer, said first seal includes a first cavity and asecond cavity, said second seal includes a first cavity and a secondcavity, said spacer includes a first leg and a second leg, said firstand second spacer legs slidingly engage said first cavity of said firstseal and said first cavity of said second seal respectively, said firstcavities of said first and said second seals each include first andsecond legs and said second cavities of said first and second seals eachinclude a first leg, said seals being a polymeric material having atensile strength of at least 5,000 psi and a flexural modulus ofelasticity of at least 300,000 psi, said first and second legs of saidfirst cavities of said seals engaging said male and female memberrespectively upon the application of pressure to said first cavity ofsaid first seal and said first cavity of said second seal and, saidfirst legs of said second cavities of said seals engaging said femalemember upon application of pressure to said second cavity of said firstseal and said second cavity of said second seal.
 2. A hydraulic couplingcomprising a male member and a female member, an annulus formed betweensaid male and female members, said female member having a first radiallyextending surface, said male member having an external circumferentiallyextending surface, a seal, said seal residing in said annulus, aretainer, said retainer abuts said seal to hold said seal in saidannular space, said female member having a recess, said seal having agenerally radially extending flange, said flange resides in said recessof said female member, said seal having a first cavity, said firstcavity facing said first radially extending surface and creating agenerally c-shaped appearance in cross section, said seal having asecond cavity, said second cavity facing said circumferentiallyextending surface of said male member and creating a generally invertedu-shape appearance in cross section, said seal being a polymericmaterial having a tensile strength of at least 5,000 psi and a flexuralmodulus of at least 300,000 psi.